renderkehu();
function renderkehu() {
    const time = document.querySelector(".header .left")
    setInterval(() => {
        const d = new Date();
        time.innerHTML = `北京时间:${d.getFullYear()}年${d.getMonth() + 1}月${d.getDate()}日${d.getHours()}时${d.getMinutes()}分${d.getSeconds()}秒`
    }, 1000);
}